I represented the algebraic structure accurately, kept each transformation valid and checked the result by substitution, graph or equivalent reasoning.
Even Better If (EBI)
I will show the missing inverse operation or algebraic step, keep signs and brackets accurate and test the result in the original relationship.
Stretch and deep challenge
Stretch: Solve 3x+2y=16 and x−2y=0.
Deep challenge: Can x+y=5 and 2x+2y=12 have a solution? Justify.